300
Serial Pulse Coder Communication Error (DTER)
Fanuc · Alpha i series AC Servo Motor
What does 300 mean?
A communication error (DTER) was detected for the serial pulse coder. This can be caused by physical damage to the signal cable, a defective pulse coder or servo amplifier module, or external electrical noise interference.
Common Causes
- Discontinuity or damage in the serial pulse coder signal cable.
- Defective serial pulse coder.
- Defective servo amplifier module.
- External electrical noise interfering with serial communication.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the continuity and integrity of the serial pulse coder signal cable.
- 2
If the cable is verified as normal, replace the pulse coder or the servo amplifier module.
- 3
Implement noise reduction measures as described in the 'Descriptions' chapter on noise.
Verified technical data. Last updated: March 2026
Related Faults
Source: Fanuc Alpha i series AC Servo Motor